Method for producing spherical particles having nanometer size, crystalline structure, and good sphericity

A method for producing nanometer-size spherical particles, comprising:

• a first step for producing intermediate spherical particles, comprising:
• melting a starting material selected from the group consisting of a metal, an alloy, and a metal compound;
• supplying the molten starting material onto a disc-shape disc which is rotated at a high speed to atomize the molten starting material into fine droplets by the action of centrifugal force, in an argon atmosphere;
• solidifying the fine droplets to form the intermediate spherical particles, the intermediate spherical particles having a particle size of 1 to 300 μm in a first atmosphere;
• and
• a second step for producing final spherical particles, comprising:
• providing a swirling plasma gas flow having the central axis thereof, the central axis running through an area between an anode and a cathode of a plasma generator;
• and
• discharging the intermediate spherical particles along the axis to subject the intermediate spherical particles to an plasma swirling treatment to collide with argon ions so as to crash the intermediate spherical particles into final spherical particles in a second atmosphere,
• wherein the final spherical particles have a particle size of less than 1 μm having a sphericity of −10% to +10%.